Background: The aim of this study was to determine the impact of sevoflurane anaesthesia on metabolic and endocrine responses to lower abdominal surgery. Methods: A prospective randomized controlled study in 20 patients undergoing abdominal hysterectomy. Patients were randomly assigned to receive either sevoflurane (S) or isoflurane anaesthesia (I). Using a stable isotope dilution technique, endogenous glucose production (EGP) and plasma glucose clearance (GC) were determined pre- and postoperatively (6,6-(2) H-2 -glucose). Plasma concentrations of glucose, insulin, cortisol, epinephrine and norepinephrine were measured preoperatively, 5 min after induction of anaesthesia, during surgery and 2 h after the operation. Results: EGP increased in both groups with no intergroup differences (preop. S 12.2 +/- 1.6, I 12.4 +/- 1.6; postop. S 16.3 +/- 1.9*, I 19.0 +/- 3.1*mumol kg(-1)min(-1), all values are means +/- SD, *P < 0.05 vs. preop.). Plasma glucose concentration increased and GC decreased in both groups. There were no differences between groups. (Glucose conc. mmol l(-1) preop.: S 4.1 +/- 0.3, I 3.9 +/- 0.5; 5 AI S 5.1 +/- 0.6*, I 5.1 +/- 1.0*, postop. S 7.0 +/- 1.0*, I 7.1 +/- 1.4*; * = P < 0.05 vs. preop.; GC ml kg(-1)min(-1) preop. S 3.0 +/- 0.4, I 3.2 +/- 0.4; postop. S 2.4 +/- 0.3*, I 2.7 +/- 0.3*; *= P < 0.05 vs. preop.) Insulin plasma concentrations were unchanged. Cortisol plasma concentrations increased intra- and postoperatively with no changes between the groups. Norepinephrine plasma concentration increased in the S group after induction of anaesthesia. I group norepinephrine was increased 2 h after operation and showed no intergroup differences. Conclusion: Sevoflurane, as well as isoflurane, does not prevent the metabolic endocrine responses to surgery.